audacia/lib-src/libnyquist/nyquist/nyqstk/src/ReedTabl.cpp

72 lines
1.8 KiB
C++

/***************************************************/
/*! \class ReedTabl
\brief STK reed table class.
This class implements a simple one breakpoint,
non-linear reed function, as described by
Smith (1986). This function is based on a
memoryless non-linear spring model of the reed
(the reed mass is ignored) which saturates when
the reed collides with the mouthpiece facing.
See McIntyre, Schumacher, & Woodhouse (1983),
Smith (1986), Hirschman, Cook, Scavone, and
others for more information.
by Perry R. Cook and Gary P. Scavone, 1995 - 2002.
*/
/***************************************************/
#include "ReedTabl.h"
ReedTabl :: ReedTabl()
{
offSet = (MY_FLOAT) 0.6; // Offset is a bias, related to reed rest position.
slope = (MY_FLOAT) -0.8; // Slope corresponds loosely to reed stiffness.
}
ReedTabl :: ~ReedTabl()
{
}
void ReedTabl :: setOffset(MY_FLOAT aValue)
{
offSet = aValue;
}
void ReedTabl :: setSlope(MY_FLOAT aValue)
{
slope = aValue;
}
MY_FLOAT ReedTabl :: lastOut() const
{
return lastOutput;
}
MY_FLOAT ReedTabl :: tick(MY_FLOAT input)
{
// The input is differential pressure across the reed.
lastOutput = offSet + (slope * input);
// If output is > 1, the reed has slammed shut and the
// reflection function value saturates at 1.0.
if (lastOutput > 1.0) lastOutput = (MY_FLOAT) 1.0;
// This is nearly impossible in a physical system, but
// a reflection function value of -1.0 corresponds to
// an open end (and no discontinuity in bore profile).
if (lastOutput < -1.0) lastOutput = (MY_FLOAT) -1.0;
return lastOutput;
}
MY_FLOAT *ReedTabl :: tick(MY_FLOAT *vector, unsigned int vectorSize)
{
for (unsigned int i=0; i<vectorSize; i++)
vector[i] = tick(vector[i]);
return vector;
}